Notropis dorsalis
Bigmouth shiner

Key Characteristics

Attaining a maximum length of about 3 inches, this small minnow has a grayish to olive-yellow back, pale silver belly and silver sides with a dark stripe down the center, running the length of the body. The head is large with a flattened ventral surface, creating a blunt triangular shape when viewed from the side. The scales nearest the head have a crowded appearance. Extending below the large, black eyes, the wide mouth of this species is overhung by its snout. As is characteristic of all native minnows, the bigmouth shiner has a single, translucent dorsal fin with less than 10 soft rays.

Status and Rank

  • State Status: SC
  • State Rank: S2
  • Global Rank: G5


County NameNumber of OccurrencesYear Last Observed
Distribution map for Notropis dorsalis

Updated 7/21/2017. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


The bigmouth shiner seems to prefer moderately fast moving creeks and streams less than 3 feet deep, but is occasionally found in larger rivers as well (McCulloch 2003).

Natural Community Types


For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.


Efforts to prevent streambank erosion and other means of sedimentation will benefit this species, as it is intolerant of highly turbid waters (McCulloch 2003). Competition with the invasive silverjaw minnow, which has similar habitat requirements, has resulted in the shrinking of bigmouth shiner distribution in Ohio (Trautman 1981). Unlike many fish species, the bigmouth shiner has shown the ability to thrive and increase its numbers in channelized waterways (Scarnecchia 1988). General management of native stream fish calls for water quality improvement through reductions in point and non-point source pollution, maintaining healthy habitat structure by limiting impoundments, dredging and other types of detrimental construction, expanding research and promoting awareness.

Active Period

Spawning from third week of May to second week of August

Survey Methods

Surveys for minnow species are generally conducted throughout the the late spring and summer using electroshockers or seine nets. Adult minnows can also be surveyed with small mesh fyke nets. In early autumn, night time electrofishing surveys for both adult and juvenile fish are used (Schneider et al. 2000).

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at [Accessed Dec 18, 2017]


Survey References

Technical References

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